The invention relates to the field of gas turbine engines and is aimed at driving an auxiliary, particularly an electric generator, mounted on an auxiliaries support.
A turbine engine comprises an auxiliaries support, known as the accessory drive gearbox assembly. The gearbox assembly comprises a number of auxiliaries, such as alternators, fuel and oil pumps, a starter and various other items. These are mechanically driven by a shaft of the turbine engine, generally by the shaft of the high-pressure spool in the case of a twin-spool turbojet.
In a turbojet, among these auxiliaries there are at least two alternators, one of which supplies the electrical power to the aircraft propelled by the turbojet and the other of which supplies the electrical power necessary for operating the turbojet itself, which is smaller than the first one. This latter alternator is generally a dynamo electric machine or permanent magnet alternator known by those skilled in the art as a PMA. In the remainder of the description, it will be termed the alternator. The alternator in particular supplies the electrical power needed for operating the turbojet control and regulation device known as the FADEC (which is the acronym for “full authority digital engine control” as it is usually termed by those skilled in the art).
The alternator rotor rotates at a very high speed, typically 18000 to 30000 revolutions per minute. At the present time, the loads (mechanical, electromechanical, etc. loads) to which the alternator is subjected during operation are not very well known. Furthermore, this alternator is frequently removed, then refitted for maintenance purposes. For this, the rotor is first of all mounted on its shaft in the gearbox assembly then the stator is bolted onto the gearbox assembly, around the rotor.